Resolve the “Entity Framework tools version '3.1.9' is older than that of the runtime '5.0.0' in Visual Studio Package Manager”

.NET 5 is released recently and you can use entity framework core 5 with your projects by setting up the version 5.0.0 of the packages, Microsoft.EntityFrameworkCore, Microsoft.EntityFrameworkCore.Design, Microsoft.EntityFrameworkCore.SqlServer, Microsoft.EntityFrameworkCore.Tools if you are using SQL server as the database. However, when you execute dotnet ef commands in the package manager console in Visual Studio you might see the message “Entity Framework tools version '3.1.9' is older than that of the runtime '5.0.0' in Visual Studio Package Manager”. Let’s see how we can get it fixed.

Running EF Commands in Builds with .NET Core 3.1 in Hosted Agents

When you run builds with Entity Framework (EF) commands such as dotnet ef migrations script with .NET Core 2.2 it would work without any issue. However, if you upgrade your projects to use .NET Core 3.1 your build may fail with issue below., when executing dotnet ef migrations script, to generate a script out of your EF migrations.
error NETSDK1045: The current .NET SDK does not support targeting .NET Core 3.1. Either target .NET Core 2.2 or lower, or use a version of the .NET SDK that supports .NET Core 3.1.

Entity Framework 7– Unapplying Migrations to Remove Migrations

In development environments accidents can happen. You could add a wrong migration and want to roll back. The option is there to remove the last migration. But if it is applied to the local db, then the changes in local db should be unapplied before removing the migration.

Let’s look at how to do this with EF 7, step by step.

The problem

Accidently view model entities added as tables to the local db.

Last added migration has created the view model entities in database.

This has happened because db context class got updated with unwanted namespace and property, while creating a view with Visual Studio.

How to fix?

Remove the unwanted namespace and property from the db context class.

Remove the last migration. But this is giving the below error.

dnx ef migrations remove

The migration '20160514193811_SessionTime' has already been applied to the database. Unapply it and try again. If the migration has been applied to other databases, consider reverting its changes using a new migration.

Option1: If the changes applied to other databases, other than local development db, the way to fix should be via a new migration correcting the issues. It is possible to remove the unwanted namespace and property from the db context class and then create a new migration, which will have drop statements to drop unwanted tables.

Option2: If the changes are only in local DB, unapply changes to local db by, updating the database into last known good migration.

dnx ef database update RemoveEventTime

This will remove last migration changes from local db.

But running is applying the unwanted migration again and remove is failing.

This is because once migration instance created using command line the changes are getting reapplied again for the, latest migration, which is the unwanted migration. The attempt to remove that get failing.

To fix this comment the db context class constructor applying the migrations.

Note: It is not a good implementation to have constructor calling Database.Migrate(). Better implementation would be having it as a separate method in the db context class and calling it explicitly, from startup.

A discussion on the same can be found here, which is saying the implementation of Database.Migrate() in the constructor is awful, which is exactly the correct way to introduce bad coding

Make sure after fixing the db context class, you have compiled the solution with a rebuild.

With this fix to “awful” code, in db context Option 2, reverting the migration by unapplying and remove works fine.

Video of January 2014 .Net Froum Session

Myself and Jaliya Udagedara in .Net Forum - January 2014.


http://digit.lk/live-blog-sri-lanka-net-forum-january-meetup/